Exosect announces breakthrough in virus formulation

Exosect Ltd. recently revealed excellent results from its virus formulation programme and has formally commenced licensing discussions. Developing robust virus formulations is currently a key area of interest for the crop protection and life sciences sectors as the potential for beneficial uses grows. These include the use of viruses as a replacement for antibiotics and as vectors of RNAi molecules all of which offer game changing potential for drug delivery and pest and pathogen control in crop protection and public health.

Scientists at Exosect have been leading the development of a novel formulation of a baculovirus, a category of virus which is routinely used against lepidopteran pests in agriculture, using their proprietary formulation platform, Entostat®. Baculoviruses are entomopathogenic DNA viruses. They have been successfully used to control a number of economically important pests, including caterpillars, sawflies and beetles. They are highly specific and leave zero residues. They can be applied up to the day of harvest and have re-entry levels of a matter of hours, however despite this excellent environmental profile, formulation challenges have limited their adoption.

Virus formulation challenges
Baculoviruses are not synthetically produced. Current production methods involve infecting live insects, harvesting the virus and repeating the process which is time consuming and resource intensive. Common to all viruses, baculoviruses are highly sensitive to ultraviolet (UV) radiation. Once applied to a crop, UV degradation can reduce efficacy significantly within 4 to 24 hours of application in full temperate sunlight.

Repeated applications are often required in order to control multiple generations of insect pests. Both of the aforementioned factors can increase costs to the grower significantly.

Exosect set out to improve the commercial viability of virus use in crop protection by developing a formulation which increases the longevity of the virus on the crop by improving its UV stability. This in turn would reduce the number of applications and make virus use in crop production a conventional option for growers.

The two year formulation development programme was carried out in collaboration with Professor Kenneth Wilson of the Lancaster Environment Centre at Lancaster University and Principal Scientist David Grzywacz of the Natural Resources Institute at the University of Greenwich, both experts in the field of insect viruses. The programme was funded by the UK’s Agritech Catalyst fund, administered by Innovate UK, the UK’s innovation agency, and co-funded by the UK’s Biotechnology and Biological Sciences Research Council.

Formulation breakthrough 
The programme included formulation development of a candidate virus, UV testing and bioassays. Exosect developed a sprayable formulation of a baculovirus which controls Spodoptera littoralis (Egyptian Cotton Leafworm), using its proprietary formulation platform, Entostat.

Initial development showed that the virus suffered no impairment through the formulation process. The formulation protected the virus throughout its journey to the insect gut where the Entostat was successfully broken down by the high pH, releasing the virus. The Entostat platform has drastically improved the virus’s ability to withstand UV degradation.

Results showed that the Entostat formulation enabled a fifty percent reduction in the amount of virus required to match the treated control. It also increased the longevity of the virus when exposed to UV radiation which will enable growers to significantly increase application intervals.

Exosect’s CEO, Andy MacNaughton comments, “This is a truly fantastic development. We have taken an active ingredient which, in its current commercial format, is restricted to a niche market. Our formulation solution has now opened up the potential for this sensitive microbial into a broader range of crop sectors and applications”.

Licensing opportunity
Exosect is now commencing licensing discussions for the intellectual property and know-how surrounding this formulation and would invite those who wish to find out more about this opportunity to join a non-confidential webinar scheduled for 1st March 2018. Contact Exosect’s Communications Manager, Georgina Donovan at info@exosect.com for more information.